Present participle; Past participle - prolonging - prolonged Present - prolong - prolong - prolongs - prolong - prolong - prolong Past - prolonged - prolonged - prolonged - prolonged - prolonged - prolonged Future - will prolong - will prolong - will prolong - will prolong - will prolong - will prolong Present conditional - would prolong - would prolong - would prolong - would prolong - would prolong - would prolong Present Perfect - have prolonged - have prolonged - has prolonged - have prolonged - have prolonged - have prolonged Past Perfect - had prolonged - had prolonged - had prolonged - had prolonged - had prolonged - had prolonged Future Perfect - will have prolonged - will have prolonged - will have prolonged - will have prolonged - will have prolonged - will have prolonged Past conditional - would have prolonged - would have prolonged - would have prolonged - would have prolonged - would have prolonged - would have prolonged Imperative - - - prolong - - - - - - - -